TO THE QUESTION ABOUT THE THEORETICAL BASIS OF DISTRIBUTION OF BRAKE FORCES WHEN BRAKING A CAR EQUIPPED WITH ABS

2021 ◽  
Author(s):  
Динь Фыонг Чан ◽  
Тхич Минь Хо
Keyword(s):  
Theoretical Basis ◽  
The Road ◽  
Emergency Braking ◽  
Braking System ◽  
Braking Distance ◽  
Braking Control

Антиблокировочная система тормозов (АБС) предназначена предотвратить блокировку колес при торможении и сохранить управляемость автомобиля. Она повышает эффективность торможения, уменьшает длину тормозного пути, позволяет обеспечивать лучшую маневренность на скользкой дороге и управляемость при экстренном торможении. В работе представлен анализ некоторых моментов взаимодействия колеса с дорогой в режиме торможения является. Anti-lock braking system is designed to prevent the wheels from locking when braking and keep the vehicle steerable. The anti-lock braking system improves braking efficiency, shortens the braking distance, provides better maneuverability on slippery roads, and emergency braking control. The paper presents the analysis of some moments of interaction of the wheel with the road in the braking mode.

scholarly journals Simulation Study of the Process of Friction in the Working Elements of a Car Braking System at Different Degrees of Wear

2018 ◽  
Vol 12 (3) ◽  
pp. 221-226 ◽  
Author(s):  
Andrzej Borawski
Keyword(s):  
Simulation Study ◽  
Friction Pair ◽  
Experimental Studies ◽  
Real Life ◽  
Operating Conditions ◽  
Heating Process ◽  
Passenger Cars ◽  
The Road ◽  
Emergency Braking ◽  
Braking System

Abstract Among the many elements of a modern vehicle, the braking system is definitely among the most important ones. Health, and, frequently, life, may rest upon the design and reliability of brakes. The most common friction pair used in passenger cars today is a disc which rotates with the road wheel and a cooperating pair of brake pads. The composite material of the pad results in changing tribological properties as the pad wears, which was demonstrated in experimental studies. The change is also facilitated by the harsh operating conditions of brakes (high and rapid temperature changes, water, etc.). This paper looks into how changing tribology reflects on the heating process of disc and pads during braking. And so a simulation study was conducted, as this method makes it possible to measure temperature in any given point and at any time, which is either impossible or extremely difficult in real life conditions. Finite element method analyses were performed for emergency braking events at various initial speeds of the vehicle reflecting the current road speed limits.

Real-Time Detection of Unsealed Surfaces During Skidding

2003 ◽  
Vol 1819 (1) ◽  
pp. 237-243
Author(s):  
Kerry J. McManus ◽  
Aaron S. Blicblau ◽  
Christopher J. Broadhurst ◽  
Ashley M. S. Carter
Keyword(s):  
Significant Degree ◽  
Emergency Braking ◽  
Emergency Situations ◽  
Passenger Vehicles ◽  
Braking System ◽  
Antilock Braking System ◽  
Road Surfaces ◽  
Timely Response ◽  
Braking Distance ◽  
Abs Algorithm

The antilock braking system (ABS) fitted to modern passenger vehicles is intended to provide reliable and efficient braking under critical road conditions or in emergency situations. Thus, ABS-equipped vehicles should remain steerable and maintain directional stability in the event of emergency braking. The ABS on vehicles operates on the principle of detection of brake lockup and release of the lockup to prevent an uncontrollable skid developing on sealed roads. However, on gravel roads or snow-covered roads braking distances can be reduced if brake lockup occurs and a wedge of gravel or snow is allowed to form in front of the wheels. The intervention of ABS prevents the wedge from forming to any significant degree, thereby extending the braking distance. An investigation was carried out of a method of discriminating between sealed and unsealed road surfaces in which a signal can be developed so that an alternative ABS algorithm can be applied specifically for gravel-covered surfaces. An attempt was made to identify and measure the buildup of gravel in front of the wheel directly, using an infrared distance-measurement sensor. Initial tests have shown that the system can provide a signal to the ABS, which will allow a timely response to enable intervention in the activation of the algorithms in the ABS.

scholarly journals Research on Virtual Test of Automobile Automatic Emergency Braking System on Ice-Snow Road

2021 ◽  
Vol 261 ◽  
pp. 02065
Author(s):  
Xianchao Zhu ◽  
Sheng Chang ◽  
Bingtao Li ◽  
Hualei Lu
Keyword(s):  
Weather Conditions ◽  
Simulation Method ◽  
Time To Collision ◽  
The Road ◽  
Injury Reduction ◽  
Emergency Braking ◽  
Virtual Test ◽  
Braking Distance ◽  
On The Road ◽  
Basic Characteristics

In view of the severe weather conditions in cold regions, the basic characteristics and braking distance of ice snow covered pavement are analyzed. This paper uses the PreScan/CarSim/Simulink software co-simulation method to test the automatic emergency braking (AEB) system on ice-snow roads. Through the appropriate adjustment of the time to collision (TTC) threshold, the car makes automatic emergency braking on the road with low friction coefficient system can achieve the effect of collision avoidance and injury reduction.

scholarly journals Sensorless Driving/Braking Control for Electric Vehicles

Actuators ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 22
Author(s):  
En-Ping Chen ◽  
Jiangfeng Cheng ◽  
Jia-Hung Tu ◽  
Chun-Liang Lin
Keyword(s):  
Electric Vehicles ◽  
Pulse Width Modulation ◽  
Functional Flexibility ◽  
Emergency Braking ◽  
Braking System ◽  
System A ◽  
High Speeds ◽  
Antilock Braking System ◽  
Braking Control ◽  
The Cost

A sensorless driving/braking control system for electric vehicles is explained in the present paper. In the proposed system, a field-oriented control (FOC) was used to integrate driving and braking controls in a unified module for reducing the cost of hardware and simultaneously incorporating functional flexibility. An antilock braking system can swiftly halt a vehicle during emergency braking. An electromagnetic reverse braking scheme that provided retarding torque to a running wheel was developed. The scheme could switch the state of the MOSFETs used in the system by alternating the duty cycle of pulse width modulation to adjust the braking current generated by the back electromotive force (EMF) of the motor. In addition, because the braking energy required for the electromagnetic braking scheme is related only to the back EMF, the vehicle operator can control the braking force and safely stop an electric vehicle at high speeds. The proposed integrated sensorless driving and electromagnetic braking system was verified experimentally.

Application of microwave Doppler displacement sensors in anti-lock braking system

2021 ◽  
pp. 43-48
Author(s):  
Dmitry V. Khablov
Keyword(s):  
Distribution System ◽  
Wheel Speed ◽  
Road Surface ◽  
The Road ◽  
Braking System ◽  
Speed Sensor ◽  
Displacement Sensors ◽  
Braking Distance ◽  
Braking Force

The issues of optimization of the vehicle anti-lock braking system are considered. To increase the reliability of the system, it is proposed to use a brake distribution system adaptive to the quality of the road surface for a quick stop of the vehicle while maintaining controllability. The system together with sensors angular wheel speed included a microwave Doppler displacement and speed sensor. The use of the specified Doppler sensor made it possible to achieve a more accurate coincidence of the dependence of the braking force on the degree of adhesion of the wheels to the road surface by monitoring the ratio between the angular and linear speeds of movement. In this way, it was possible to minimize the braking distance of the vehicle while maintaining controllability under various driving conditions.

scholarly journals Description and tests of a control system for automatic emergency braking of a car with an algorithm for predicting the adhesion of automobile tires to the road surface

2021 ◽  
Vol 2061 (1) ◽  
pp. 012100
Author(s):  
V V Petin ◽  
A V Keller
Keyword(s):  
Climatic Conditions ◽  
Multimedia System ◽  
Main Task ◽  
Driver Assistance ◽  
Adhesion Properties ◽  
The Road ◽  
Emergency Braking ◽  
The World ◽  
Braking Distance ◽  
Automatic Action

Abstract Every year the number of cars in the world is steadily growing, which in turn leads to an increase in road accidents. Russia, as the largest country by area in the world, has a number of traffic-related features that are not typical for other regions, including changing road and climatic conditions. The sharp increase in the number of accidents in the first hours after precipitation is especially noticeable, that indicates the difficulty to adapt to the changing traffic situation for vehicle drivers. More than 60% of collisions, according to the traffic police databases for 2018-2019, occur due to incorrect predictions by drivers of the braking distance of their cars. As a rule, this can happen due to the inexperience of the driver, incorrect assessment of the current adhesion properties of the roadway, distraction to a mobile phone, the climate or multimedia system of the car, movement with insufficient visibility. Preventing collisions occurring in such scenarios is the main task of an intelligent driver assistance system such as the automatic emergency braking system. The main part of this system is an adequate assessment of dynamically changing road and climatic conditions and warning the driver of a possible collision hazard, as well as automatic action on the vehicle’s brake drive to prevent a collision. The article describes control algorithms for assessing and predicting dangerous situations.

scholarly journals TECHNOLOGICAL MEASURES OF FOREFRONT ROAD IDENTIFICATION FOR VEHICLE COMFORT AND SAFETY IMPROVEMENT

Transport ◽  
2019 ◽  
Vol 34 (3) ◽  
pp. 363-372 ◽  
Author(s):  
Vidas Žuraulis ◽  
Vytenis Surblys ◽  
Eldar Šabanovič
Keyword(s):  
Image Analysis ◽  
Traffic Safety ◽  
Laser Scanning ◽  
Road Surface ◽  
The Road ◽  
Emergency Braking ◽  
Braking System ◽  
Safety Improvement ◽  
Road Friction ◽  
Surface Irregularities

This paper presents the technological measures currently being developed at institutes and vehicle research centres dealing with forefront road identification. In this case, road identification corresponds with the surface irregularities and road surface type, which are evaluated by laser scanning and image analysis. Real-time adaptation, adaptation in advance and system external informing are stated as sequential generations of vehicle suspension and active braking systems where road identification is significantly important. Active and semi-active suspensions with their adaptation technologies for comfort and road holding characteristics are analysed. Also, an active braking system such as Anti-lock Braking System (ABS) and Autonomous Emergency Braking (AEB) have been considered as very sensitive to the road friction state. Artificial intelligence methods of deep learning have been presented as a promising image analysis method for classification of 12 different road surface types. Concluding the achieved benefit of road identification for traffic safety improvement is presented with reference to analysed research reports and assumptions made after the initial evaluation.

scholarly journals FEATURES OF ADAPTIVE BRAKE CONTROL OF THE SECONDARY BRAKE SYSTEM OF A MULTI-AXLE VEHICLE

2021 ◽  
pp. 27-37
Author(s):  
Viktor Bogomolov ◽  
Valeriy Klimenko ◽  
Dmytro Leontiev ◽  
Oleksandr Kuripka ◽  
Andrii Frolov ◽  
...  
Keyword(s):  
Simulation Model ◽  
Road Safety ◽  
Road Surface ◽  
Brake System ◽  
Technical Literature ◽  
Adhesion Properties ◽  
The Road ◽  
Emergency Braking ◽  
Braking System ◽  
Braking Process

Problem. A malfunction of the service braking system of a wheeled vehicle (CTS) significantly affects road safety, especially when operating multi-axle vehicles with large masses. One of the ways to increase the level of road safety of multi-axle vehicles, when braking them using a spare (emergency) braking system, is the introduction of automated adaptive braking systems into the design of the brake drive of vehicles. The definition of the limits of the use of the adaptive braking system on vehicles with many axles is almost not disclosed in the scientific and technical literature, therefore, the issue of using such a system on vehicles with a large number of axles requires additional research. Purpose. The purpose of this work is to develop a simulation model for adaptive control of the braking process of a multi-axle vehicle using a spare (emergency) braking system, taking into account the simulation of the dynamics of the drive and the variability of the adhesion properties between the tire of the vehicle wheel and the road surface. Methodology. To achieve this goal, it is necessary to develop a simulation model of the brake drive in an adaptive mode, implement a model of the interaction of the tire with the road surface, and implement a model of the braking dynamics of a multi-axle vehicle in the event of a malfunction of its service brake system. Originality. The proposed key criterion (Kr) for changing the throttle section in electro-pneumatic pressure modulators, which provide adaptive air inlet or outlet from the corresponding brake chambers of the drive, during simulation, made it possible to simulate the operation of the drive circuits in the adaptive mode. It has been established that, depending on the potential for the realization of the adhesion between the tires of automobile wheels and the road surface, the pressure in the electro-pneumatic brake drive with its adaptive regulation can be increased by no more than 0.04 MPa.

scholarly journals Proposal of advanced emergency braking system adapted to the road surface condition

2018 ◽  
Vol 84 (860) ◽  
pp. 17-00311-17-00311
Author(s):  
Shunsuke TSUKUDA ◽  
Yuki SHIOZAWA ◽  
Hiroshi MOURI
Keyword(s):  
Surface Condition ◽  
Road Surface ◽  
The Road ◽  
Emergency Braking ◽  
Braking System

scholarly journals Assessment of the functional functionality of passenger car brake systems by changing the braking distance during operation

2021 ◽  
Vol 13 (1) ◽  
pp. 78-86
Author(s):  
Alexander Nazarov ◽  
◽  
Vitalii Kashkanov ◽  
Ivan Nazarov ◽  
Yevhen Ivanchenko ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Passenger Cars ◽  
Passenger Car ◽  
Emergency Braking ◽  
Braking System ◽  
Braking Distance ◽  
Braking Force ◽  
Braking Process ◽  
Relative Change

The article discusses a methodology for assessing the functional suitability of brake systems to change the braking path of passenger cars, taking into account various operating conditions. The goal is achieved by using the method of mathematical modeling of the emergency braking process, taking into account the possible operating conditions of cars performing emergency braking at certain initial speeds, in particular, exceeding 100 km / h. Based on the analysis of scientific sources, it has been established that the determination of the braking efficiency of a vehicle classically occurs on the verge of blocking all wheels with known methods of distributing braking forces between the axles of the vehicle. In this case, the standards set the maximum value of the minimum deceleration and braking distance. In addition, the jump in the maximum possible value of the braking force between the wheels of each axle makes it possible to compare it with the requirements of DSTU 3649: 2010, and the assessment of the magnitude of this jump for each braking of the car is to establish its functional suitability. As a result, according to the magnitude of the jump in the maximum possible value of the braking distance, the change in the maximum allowable braking force of the car sets, and according to the magnitude of its jump, it is possible to assess the functional suitability of its braking system. As a result, the use of expert information on the value of jumps in the maximum possible value of the braking force of a car, affecting the braking torques and braking coefficient, can reduce the amount of experimental research and significantly reduce the time to reach an objective decision on the functional suitability of the brake systems of operated cars. The paper presents the results of theoretical studies of passenger cars Chevrolet Aveo, Lada Priora and Forza with different loads, performing emergency braking at an initial speed of 40-150 km / h on a road with dry asphalt concrete. The boundaries of the coefficient of the relative change in the braking distance of the tested passenger car, at which it is possible to make a conclusion about the functional suitability of its braking system, have been established.

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